(rotary usage) pad flat or not ?

C

chip douglas

New member
I'm getting confused some, cause i hear both versions........some say it is mandatory to keep pad flat as possible to avoid introducing new swirls, and some say flat pad cause more heat, thus more risk of burning the paint, both sides are pretty convincing i must say, but let's the people speak :-p lol
 
Yes. Generally you want to keep the pad flat because edges cause excess heat and you get more coverage. But, it is still possible to use an edge and keep it flat if you use less pressure.



Ryan
 
My .02 cents Chip...



The primary reason you would lift the buffer at all is to avoid cutting too much paint on an edge, when you're rolling over the end of a panel, say a hood etc. In other words;





Most right handed people will naturally focus the pressure of the buffer on the 12 o'clock to 5 o'clock area of the pad , since they're moving left to right in their passes (or should be). By lifting up slightly on the left side of the buffer as you approach that edge, you prevent cutting the paint down unevenly on the edges there when your right side is overlapping the edge, or "hanging 10" as I like to say. Remember; you don't want to run the buffer up TO the edge of a panel, but OVER it, because the outer edge of any pad is perhaps the most dangerous to that thin area of the paint.



Otherwise, you DO want to keep it flat as possible, and with as even - handed pressure applied as humanly possible. If you tilt in the middle of a panel, you'll risk getting buffer marks or holograms from the polish or compound, and just undermine what you're attempting to clean up.



If you keep a rotary moving, chances are you will NEVER burn or cut through the paint in the middle of a panel. However, if you aren't careful around the edges and ridges of a panel, and you don't "roll off" past the edges with a slight tilt on the left side of the buffer, you can remove enough paint there by the left side of the pad hitting /slapping that edge where the paint is naturally thinner. I always recommend a beginner TAPE OFF edges and ridges. Even pros do this, it's insurance. Even with the above technique, you would still need to protect the very edge because the middle of your buffing pad would be on top of it as you "roll off' the right side of the pad over the edge, and you'd see no paint left there afterwards. You can remove the(masking) tape prior to doing your your final pass or 2 to even and polish everything up uniformly.



Hope this makes sense.

:)
 
Yep, that makes a lot of sense, but i'm witting back on this only to make sure i got it right(i err on caution side so...)



For instance today, i was doing a toyota tercel ; i taped everything rubber or plastic round that car + on door panel i taped the body line that runs between the molding and top of door, as the clearance is about 6 inches and my pad 8 inches(3m polishing pad). Doing the hood and trunk i popped them open so it was easier to run off the edges. When doing fenders i get very tense so to speak, althought i was using the 5937 from 3m. So on fenders and top rear sides(these are much like fenders, as they have round edges and places where pad could burn paint easily) i tilted the buffer and ran it on them but very fast, moving with the bend(or round edge).......is this ok ?



Doing the hood, where do you place yourself ? in front of it, or on the side ? As to me i placed in fron to do the middle part and on the sides to do the sides(left and right) of the hood. The lower front part of the hood goes round as well, so i guess you move with it, tiltingthe pad so the middle doesnt sit on top of the curve, is this correct ? Doing them i never insist, i make about 2-3 quick passes, no more.



Please bear with me Guitarman, as i really need help on this and insist on doing good quality jobs. I literally freak on those rounded parts mentioned above, like fenders, and top rear sides, there s no flat surface there at all, so what i do is move with the curves.........i only use say half the pad there, so the middle part doesnt abrade the ridge of the curve.



Also, that toyota tercel has angled/curved bottom door panels, what i did was move up and down alongside that part.......i mean i ran the buffer on an up and down motion so as to flow with the curves, and this going left to right till it was completely done.........is this correct ? I also tried to figure out a way to do that part otherwise but i didnt find any better way then moving with the curves........sorry if i sound a bit erratic, im so beat :(



Now on hood ridges ; the ridge has an upper part(a peak) and a lower part(a velley so to speak)...i just position my pad so i dont run on the ridge.........i do the upper part, then the lower part, but never am i buffing on the ridged curve.



What is the outer edge of the pad(i know it sound stupid to ask but ..) let s say im facing the hood, doing a side of it, moving left to right, then the outter edge would be the part that would hit or slap the edge of the fender panel if i didnt tilt it,right ?



Gee buddy, if i can get this cleared upl, ill be in heaven :xyxthumbs



By the way, as i said im a bit sorry to ask so much, but i have trust in you and appreciate your help a WHOLE lot.



Regards
 
Most of that sounds pretty good and reasonable Chip, nothing there too eggregious to comment on. Here's some of my approach, which you have to accept *may* not be how others do it, but how I was taught and what works for me. Don't take it as the Holy Grail per se'. Many others here are certainly skilled with a rotary and can also chime in.



When I do most hoods, I stand on the fender side also and tackle each half at a time, because most hoods are longer from bumper to windshield than side to side, so there isn't much stretching involved when standing along the fender. Make sure your cord is over your shoulder. I like a button down collar shirt when buffing a whole car so I can tuck the cord under the collar and button it off, so the cord won't fall off my neck and hit the paint.



On flat horizontal panels, the norm is to buff left to right, in ~2ft to 3 foot sections , and your pattern should generally be up/down, then back and forth (perpindicular) then at a 45 degree across the area. This can't always be done on every panel of the car of course, especially the sides and lower rockers, but if you can approximate it by using OVERLAPPING motions (up down/back forth), that's the way to go. Rolling off edges and opening doors, hoods , trunk etc. is a good idea and should always be done. Just try and follow the contours and NEVER try to force the buffer into a tight corner, such as between an antenna and a windshield at the back of the hood or trunk, because you can't move the machine enough to prevent heat build up, and burn thru or blistering can result. Better to tackle some of those places by hand.



I would rather you taped the ridges on the hood etc. but if you feel you're able to avoid it while still working up to it, ok I guess. Mistakes will happen , and most of them you won't ever realize till you're done. The polish covers up burn throughs pretty well till it's polished off. Convex ridges are more prone to thin paint than concave contours of course. On rounded areas , you don't have to generally do the "lift" thing so much, just lighten up pressure wise on the tool and follow the contours as best as possible.



When referring to the "outer edge" of the pad, simply means the periphery of the pad, where the pad ends, and in relation to the "lifting" part, you just don't want the left edge against the end of the panel when you're rolling off the edge with the right side of the buffer.



You are exercising common sense I think, and caution. The biggest thing is keep moving the tool and don't trigger it on and off or vary the RPM's much while on the paint, keep a steady speed. Spur the pad after a panel or 1/2 hood if need be, the compound will not be as effective otherwise. Most of the damage people do with rotarys is caused by not moving and using way too high an RPM for what they're trying to do. This is why a novice should never buy or use a fixed ( 3 speed etc.) speed rotary. Variable speed isn't a luxury, it's mandatory for paintwork such as we do.
 
Remember, the high speed turns clockwise so use more pressure on the "right" side of the pad not the "left". This way you will be using the roatation and not digging in and catching the edge.





Ryan
 
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